On Thu, Nov 03, 2016 at 10:47:58AM +0200, Felipe Balbi wrote:
>
> Hi,
>
> Peter Chen <peter.chen@xxxxxxx> writes:
> > For isoc endpoint descriptor, the wMaxPacketSize is not real max packet
> > size (see Table 9-13. Standard Endpoint Descriptor, USB 2.0 specifcation),
> > it may contain the number of packet, so the real max packet should be
> > ep->desc->wMaxPacketSize && 0x7ff.
> >
> > Cc: Felipe F. Tonello <eu@xxxxxxxxxxxxxxxxx>
> > Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
> > Fixes: 16b114a6d797 ("usb: gadget: fix usb_ep_align_maybe
> > endianness and new usb_ep_aligna")
> >
> > Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
> > ---
> > include/linux/usb/gadget.h | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
> > index 8e81f9e..cce2db6 100644
> > --- a/include/linux/usb/gadget.h
> > +++ b/include/linux/usb/gadget.h
> > @@ -429,7 +429,10 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
> > */
> > static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
> > {
> > - return round_up(len, (size_t)le16_to_cpu(ep->desc->wMaxPacketSize));
> > + int max_packet_size = (size_t)le16_to_cpu(ep->desc->wMaxPacketSize)
> > + && 0x7ff;
> > +
> > + return round_up(len, max_packet_size);
> > }
>
> care to update this to use new usb_endpoint_maxp()?
>
But it is a bug existed at v4.9, the usb_ep_align returns wrong request
length for isoc. I found this bug by running usbtest.
--
Best Regards,
Peter Chen
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